1. Field of the Invention
The present invention generally relates to trays for disc drives, and particularly to a tray for a disc drive which can effectively reduce noise and vibration of an optical disc loaded on the tray when the optical disc rotates at high speed.
2. Related Art
Tray-loading type optical disc reading/playing (“reproducing”) devices typically include CD-ROM (compact disk-read only memory) drives, DVD-ROM (digital video disc-read only memory) drives and CD audio players. Referring to FIG. 5, this shows a loading tray 1a of a typical tray-loading type optical disc reproducing device, together with an optical disc 30a. In order to prevent the optical disc 30a from being detached from the loading tray 1a when the tray-loading type optical disc reproducing device is operated in a vertical orientation, a plurality of hooks 46a is provided on a peripheral portion 40a of an optical disc receiving region 20a of a main body 10a of the loading tray 1a. 
Each hook 46a extends radially inwardly from the peripheral portion 40a of the disc receiving region 20a. In cases where the loading tray 1a is vertically oriented, the optical disc 30a received in the disc receiving region 20a may be retained by the hooks 46a, thereby preventing the optical disc 30a from detaching from the loading tray 1a. 
Most trays for disc drives are made of a plastic material, such as ABS (Acrylonitrate-Butadiene-Styrene), PC (Polycarbonate), or a combination of ABS plus PC. Such trays are made by an injection molding process. In the case of the loading tray 1a, an upper mold and a lower mold of an injection mold interface along a path that is generally parallel to an upper surface of the main body 10a. In order to form the hooks 46a and allow easy separation of the upper mold from the lower mold along a single axis, a plurality of mold releasing holes 44a is defined in the disc receiving region 20a below the corresponding hooks 46a. To ensure that the hooks 46a are properly shaped, the mold releasing holes 44a are generally slightly larger than areas of horizontal portions of the hooks 46a. Thus when the injection mold is opened, upper mold is easily moved away from lower mold, and the loading tray la can be released from the lower mold by eject rods or an eject plate.
As shown in FIG. 6, when the optical disc 30a is rotated at high speed by a spindle motor, a first airflow 300a flowing over the optical disc 30a and a second airflow 300b flowing under the optical disc 10a are produced. The first airflow 300a may generally flow smoothly over the optical disc 30a. Portions of the second airflow 300b exit through the mold releasing holes 44a. However, the mold releasing holes 44a are generally too small to allow the second airflow 300b to smoothly flow therethrough. That is, the second airflow 300b is retarded and generates turbulence at the mold releasing holes 44a. Thus noise is also generated. The turbulence may also cause the optical disc 10a to vibrate. All in all, the mold releasing holes 44a are prone to generate noise and vibration of the optical disc 10a. 
Therefore, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.